/**
 * 多边形
 * @module zrender/shape/Polygon
 * @author Kener (@Kener-林峰, kener.linfeng@gmail.com)
 * @example
 *     var Polygon = require('zrender/shape/Polygon');
 *     var shape = new Polygon({
 *         style: {
 *             // 100x100的正方形
 *             pointList: [[0, 0], [100, 0], [100, 100], [0, 100]],
 *             color: 'blue'
 *         }
 *     });
 *     zr.addShape(shape);
 */
/**
 * @typedef {Object} IPolygonStyle
 * @property {string} pointList 多边形顶点数组
 * @property {string} [smooth=''] 是否做平滑插值, 平滑算法可以选择 bezier, spline
 * @property {number} [smoothConstraint] 平滑约束
 * @property {string} [brushType='fill']
 * @property {string} [color='#000000'] 填充颜色
 * @property {string} [strokeColor='#000000'] 描边颜色
 * @property {string} [lineCape='butt'] 线帽样式，可以是 butt, round, square
 * @property {number} [lineWidth=1] 描边宽度
 * @property {number} [opacity=1] 绘制透明度
 * @property {number} [shadowBlur=0] 阴影模糊度，大于0有效
 * @property {string} [shadowColor='#000000'] 阴影颜色
 * @property {number} [shadowOffsetX=0] 阴影横向偏移
 * @property {number} [shadowOffsetY=0] 阴影纵向偏移
 * @property {string} [text] 图形中的附加文本
 * @property {string} [textColor='#000000'] 文本颜色
 * @property {string} [textFont] 附加文本样式，eg:'bold 18px verdana'
 * @property {string} [textPosition='end'] 附加文本位置, 可以是 inside, left, right, top, bottom
 * @property {string} [textAlign] 默认根据textPosition自动设置，附加文本水平对齐。
 *                                可以是start, end, left, right, center
 * @property {string} [textBaseline] 默认根据textPosition自动设置，附加文本垂直对齐。
 *                                可以是top, bottom, middle, alphabetic, hanging, ideographic
 */


var Base = require('./Base');
var smoothSpline = require('./util/smoothSpline');
var smoothBezier = require('./util/smoothBezier');
var dashedLineTo = require('./util/dashedLineTo');
/**
         * @alias module:zrender/shape/Polygon
         * @param {Object} options
         * @constructor
         * @extends module:zrender/shape/Base
         */
var Polygon = function (options) {
    Base.call(this, options);    /**
             * 多边形绘制样式
             * @name module:zrender/shape/Polygon#style
             * @type {module:zrender/shape/Polygon~IPolygonStyle}
             */
                                 /**
             * 多边形高亮绘制样式
             * @name module:zrender/shape/Polygon#highlightStyle
             * @type {module:zrender/shape/Polygon~IPolygonStyle}
             */
};
Polygon.prototype = {
    type: 'polygon',
    /**
             * 创建多边形路径
             * @param {CanvasRenderingContext2D} ctx
             * @param {module:zrender/shape/Polygon~IPolygonStyle} style
             */
    buildPath: function (ctx, style) {
        // 虽然能重用brokenLine，但底层图形基于性能考虑，重复代码减少调用吧
        var pointList = style.pointList;
        // 开始点和结束点重复
        /*
                var start = pointList[0];
                var end = pointList[pointList.length-1];

                if (start && end) {
                    if (start[0] == end[0] &&
                        start[1] == end[1]) {
                        // 移除最后一个点
                        pointList.pop();
                    }
                }
                */
        if (pointList.length < 2) {
            // 少于2个点就不画了~
            return;
        }
        if (style.smooth && style.smooth !== 'spline') {
            var controlPoints = smoothBezier(pointList, style.smooth, true, style.smoothConstraint);
            ctx.moveTo(pointList[0][0], pointList[0][1]);
            var cp1;
            var cp2;
            var p;
            var len = pointList.length;
            for (var i = 0; i < len; i++) {
                cp1 = controlPoints[i * 2];
                cp2 = controlPoints[i * 2 + 1];
                p = pointList[(i + 1) % len];
                ctx.bezierCurveTo(cp1[0], cp1[1], cp2[0], cp2[1], p[0], p[1]);
            }
        } else {
            if (style.smooth === 'spline') {
                pointList = smoothSpline(pointList, true);
            }
            if (!style.lineType || style.lineType == 'solid') {
                // 默认为实线
                ctx.moveTo(pointList[0][0], pointList[0][1]);
                for (var i = 1, l = pointList.length; i < l; i++) {
                    ctx.lineTo(pointList[i][0], pointList[i][1]);
                }
                ctx.lineTo(pointList[0][0], pointList[0][1]);
            } else if (style.lineType == 'dashed' || style.lineType == 'dotted') {
                var dashLength = style._dashLength || (style.lineWidth || 1) * (style.lineType == 'dashed' ? 5 : 1);
                style._dashLength = dashLength;
                ctx.moveTo(pointList[0][0], pointList[0][1]);
                for (var i = 1, l = pointList.length; i < l; i++) {
                    dashedLineTo(ctx, pointList[i - 1][0], pointList[i - 1][1], pointList[i][0], pointList[i][1], dashLength);
                }
                dashedLineTo(ctx, pointList[pointList.length - 1][0], pointList[pointList.length - 1][1], pointList[0][0], pointList[0][1], dashLength);
            }
        }
        ctx.closePath();
        return;
    },
    /**
             * 计算返回多边形包围盒矩阵
             * @param {module:zrender/shape/Polygon~IPolygonStyle} style
             * @return {module:zrender/shape/Base~IBoundingRect}
             */
    getRect: function (style) {
        if (style.__rect) {
            return style.__rect;
        }
        var minX = Number.MAX_VALUE;
        var maxX = Number.MIN_VALUE;
        var minY = Number.MAX_VALUE;
        var maxY = Number.MIN_VALUE;
        var pointList = style.pointList;
        for (var i = 0, l = pointList.length; i < l; i++) {
            if (pointList[i][0] < minX) {
                minX = pointList[i][0];
            }
            if (pointList[i][0] > maxX) {
                maxX = pointList[i][0];
            }
            if (pointList[i][1] < minY) {
                minY = pointList[i][1];
            }
            if (pointList[i][1] > maxY) {
                maxY = pointList[i][1];
            }
        }
        var lineWidth;
        if (style.brushType == 'stroke' || style.brushType == 'fill') {
            lineWidth = style.lineWidth || 1;
        } else {
            lineWidth = 0;
        }
        style.__rect = {
            x: Math.round(minX - lineWidth / 2),
            y: Math.round(minY - lineWidth / 2),
            width: maxX - minX + lineWidth,
            height: maxY - minY + lineWidth
        };
        return style.__rect;
    }
};
require('../tool/util').inherits(Polygon, Base);
module.exports = Polygon || module.exports;;